1. Field of the Invention
The present invention relates to a firm forming apparatus and a method of film formation.
2. Description of the Related Art
As a producing method of a piezoelectric film of a piezoelectric actuator used, for example, in an ink-jet head for an ink-jet printer or the like, a method called as an aerosol deposition method (AD method) is available. The AD method is a method of forming a piezoelectric film by jetting a substance (aerosol), in which fine particles of a piezoelectric material such as Lead Zirconate Titanate (PZT) or the like is dispersed in a gas, toward a surface of a substrate such that the fine particles are collided and deposited onto the substrate. This producing method has been used not only for forming the film of a piezoelectric material, but also for forming a film of a ceramics material and a metallic material.
For example, in Japanese Patent Application Laid-open No. 2003-293159, an apparatus which performs a film formation by using such AD method is disclosed. This apparatus includes an aerosol forming chamber which generates an aerosol, a film forming chamber in which the aerosol generated is jetted onto a substrate, and a jetting nozzle which is provided inside the film forming chamber. When an exhaust pump (air discharge pump) connected to the film forming chamber is operated, the aerosol generated in the aerosol forming chamber is accelerated to a high velocity by a differential pressure between the aerosol chamber and the film forming chamber, and is jetted from the jetting nozzle. Particulate material contained or included in the jetted aerosol are collided and deposited on the substrate, thereby forming a film on the substrate.
In such an apparatus, however, the aerosol jetted from the jetting nozzle flows in a direction of exhaust upon being drawn by an exhaust flow by the exhaust pump in some cases. In such a case, the particulate material is deposited thickly in the direction of exhaust, and a uniform formation of the film is hindered.